Wiring an outdoor shed can be relatively simple

Gary Dymski, Tribune Newspapers: NewsdayCHICAGO TRIBUNE

After putting myself through five hours of digging, drilling and yanking on wire in hot, humid weather, my back-yard shed had electricity.

My 10-by-14-foot wood shed is a lifesaver for winter storage of pool and garden equipment and patio furniture. During summer months, it is a near-perfect hideaway ("Where's Dad?") and spacious enough to be a combination workroom and changing room. At nightfall, however, without electricity, our shed left us stumbling around with flashlights.

Supplying an outdoor structure with electricity can be relatively simple. Underground-feed (UF) wire is run from an electric service panel (I used the service subpanel installed outdoors for my in-ground pool). At the panel, the UF wire is connected to a circuit breaker. Inside the shed, the wire connects to a ground fault circuit interrupter (GFCI) outlet. From that outlet in the shed, another outlet, light and light switch can be added.

Completing such a task takes a reasonable amount of electrical knowledge and some materials (conduit, fittings, a GFCI outlet, a single-pole switch and UF wire), totaling about $50.

Before sharing my experience, here's a warning: You should not attempt to wire from your service panel without some experience. In addition to general electrical knowledge, be sure your service panel can support another breaker. (Blank slots in your service panel likely mean you can add new circuits). Finally, before doing any work, check with the building department in your town or village.

To begin "enlightening" your shed or outdoor structure, dig a 2-foot-deep trench from the subpanel to the front of the shed (for my job, about a 60-foot distance). Next, roll 12-gauge (UF) wire into the trench, leaving some excess (3 to 5 feet) at each end. Bury the wire, making sure to tamp the soil and reposition the sod for a neat job.

Turn off the power to the subpanel, then run the excess wire at the subpanel through half-inch PVC conduit (cut to 4 feet in length with a hacksaw) into the service panel. To do this, knock out a precut slot at the bottom of the panel, run the wire through the PVC conduit, then slip the wire at the front end of the conduit through the precut slot, allowing excess wire to hang free. To secure the conduit, first use PVC glue to attach a half-inch fitting with threaded end. The threaded end is secured to the knocked out slot with a fitting ring. Bury the conduit and exposed wire.

Next, with the power still off, cut and strip wire to proper lengths and wire the circuit breaker. The black, or hot, wire will screw onto the breaker. The white, or neutral, wire will screw onto the neutral bar on the subpanel. The bare wire, or ground, screws onto the ground bar on the panel. Locate these bars by examining the existing circuits; white is wired to neutral, black to hot, ground to ground. To finish at the subpanel, snap the breaker into its slot.

At the other end, where the wire will enter the shed, use a 1-inch spade bit to drill through the shed siding. Attach another piece of PVC conduit (about 2 feet in length) to an LB fitting. Connect with PVC glue and secure the fitting to the interior of the wall with a fitting ring. Before securing the LB fitting or gluing, be sure to run the wire through the fitting into the shed.

Once the LB fitting is secure and the wire is inside the shed, wire the GFCI following the manufacturer's directions. If you are adding outlets to the GFCI in a circuit run, connect the wires from the subpanel to the line terminals (white wire to silver screw, black wire to brass) on the GFCI. Then connect the wires going to the next outlet on the load terminals (white to silver, black to brass). This will provide GFCI protection for all the outlets in the run.

My shed has only a second outlet, which supplies power to the switch for the light fixture. To supply power, a loop must be created between the final outlet in the run and the switch. Mount and wire a single-pole light switch just inside the shed door. From this switch, run wire to where the light fixture will be located. Wire from the second outlet and the switch is connected at the fixture to create a loop.

Presto. Only when all the wiring was completed was power to the subpanel turned back on.